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K-State Turf and Landscape Blog

Author: Brooke Stiffler

Tips for submitting a ‘digital sample’ to plant disease diagnostic lab

By Lucky Mehra

When it comes to plant health, physical samples are best. However, sometimes it is not practical to send physical samples, such as with large trees or shrubs. A digital sample can be a good alternative or a good first step. By ‘digital sample’ we mean submitting digital images of the plant problem to the KSU plant disease diagnostic clinic.

Consider the following tips to take the photos and provide all the relevant information to help us diagnose the problem quickly and correctly.

Pictures

The main component of a ‘digital sample’ is the set of digital images itself. Take the following types of pictures to help us understand both the ‘big’ and ‘small’ picture of the problem. Make sure that the plant or plant part is in focus when taking pictures. Some phones are pretty good at auto focus, but most of the time you will need to tap on the screen at the point of interest to guide your camera to focus at a particular point.

  • Take pictures from a distance to give us the landscape view or the ‘big picture view’. It should include the whole tree/shrub along with neighboring plants (Fig. 1).

Fig. 1. The Hawthorn tree in the foreground has leaf spots. This image is to give an overall view of the landscape. For example, proximity of the tree to the concrete and adjoining trees.

  • Photo of the affected plant(s) i.e. the plant(s) showing the problem.
  • Photo of the affected plant part, whether it is leaf, flower, stem, twig, or root (FIg. 2).

Fig. 2. Affected leaves of the hawthorn tree.

  • Try to take a close-up shot of the problem symptoms (Fig. 3). If there are signs (actual parts of the pathogen i.e. fungal mycelium or other structures) present on the plant part, try to zoom in, tap to focus, and then take the photo. Take multiple photos to ensure that you will have at least a few good quality ones. If you have access to a microscope, you can bring the affected plant part to your home or office and focus it under the microscope. With some patience, you can also take really good macro shots with your phone through the eyepiece lens. Many of our students take photos this way in the lab. 

Fig. 3. An example of close-up images of a hawthorn leaf (top side of leaf on the left, and underside of leaf on the right) with yellow spots taken with a phone camera, without any additional lens attachment.

Additional essential information

Sometimes, the plant problem is very peculiar, and it is easy to identify by just looking at the photos you submit (e.g. yellow spots on hawthorn leaves shown above are the symptoms of Cedar-hawthorn rust); however, most of the time it is not possible to diagnose a problem only based on photos. We need much more information from you to help us with the correct diagnosis. Provide as much information as you can. Please see below for the type of information that will be useful to us when making the diagnosis.

Site history and pattern

Make sure to provide information about the site where the shrub or tree is located. That information may include soil type if known, soil pH, slope, distance to the concrete sidewalk or road etc. 

Are there any drainage problems? Is this the only plant affected? Are other plants of the same species affected? If yes, what is the pattern of these plants in the landscape i.e. is there a cluster of affected plants or the distribution is random? Are other plant species affected?

Plant pattern

Tell us about the affected plant part whether it is leaf, stem, flower, twig, stem or root. Additionally, report the location of symptoms on the plant. Some problems tend to occur on younger leaves, others are specific to older leaves. All this information can help us rule out some issues and narrow down the diagnosis.

Timing of the symptom appearance.

Was there any weather event such as temperature (too hot or too cold) or moisture extremes (e.g. heavy rainfall) prior to the symptom development. We can download these data from a local weather station as well, however, rainfall events can be non-uniform over the whole area covered by a weather station. So if you have onsite information about the weather data, report it to us.

Chemical history

Any history of chemical or fertilizer application should be provided. This can help the diagnostician in figuring out if the problem is arising due to chemical exposure or due to a biotic agent.

Euonymus Scale

By Brooke Garcia

This is the time during the summer season when Euonymus Scale may be extra noticeable on evergreen euonymus. The scale insect will appear as small, white dots covering the planting. If you are wearing darker clothing and come into contact with the shrub, you may notice the white “debris” coming off of the plant. The plant can quickly become infested and covered with this insect. Euonymus Scale is capable of killing the plant if left untreated. Keep a watchful eye on plantings during this time. There are cultural strategies that can be incorporated into the garden to reduce the likelihood of this insect becoming a problem, but it is extremely prevalent and may require chemical treatment.

Euonymus Scale Infestation On Euonymus Plants Located Near Building (Auth-Raymond Cloyd, KSU)

For more information about the biological characteristics of this insects, as well as cultural and chemical practices that can aid in prevention and/or treatment, visit the K-State Extension Entomology post here: https://blogs.k-state.edu/kansasbugs/2020/07/02/euonymus-scale-4/

USGA Highlights Kansas City’s Professional Sports Venues

By Dr. Jack Fry
The USGA recently released a video that demonstrates how important their research support is to the turf industry.  Not only does the research they’ve supported impact the golf industry, but it also carries over to other sports and the lawn and landscape industry as well.  This video (link below) focuses on the sports turf managers at Kauffman Stadium (Trevor Vance), Arrowhead Stadium (Travis Hogan), and Children’s Mercy Park (Casey Montgomery).  Over the years, the USGA has also been very supportive of K-State’s turf research.  Not only that, the current Director of the USGA Turf and Environmental Research Program, Dr. Cole Thompson, is a K-State alum.

https://www.usga.org/content/usga/home-page/videos/2020/05/18/200507-golf-journal—kansas-city-turf-100-years-g-6157422087001.html

Brown Patch on Tall Fescue

By: Ward Upham

(Article from June 30th, 2020 Horticulture e-Newsletter)

We have been receiving numerous reports of brown patch showing up on tall fescue. This disease is favored by warm night temperatures and extended periods of leaf wetness. If you go outside in the morning and the lawn is covered with dew and the temperature is in the high 60s or higher, it means that conditions are getting right for brown patch. The fungus is primarily a leaf pathogen and does not attack the roots. During severe outbreaks, the fungus may invade the lower leaf sheaths and crown and kill plants. But in most cases, the turfgrass can recover from brown patch. This recovery may take two to three weeks, depending on weather. To read more, visit the Horticulture e-Newsletter: https://hnr.k-state.edu/extension/info-center/newsletters/2020/June30_2020_26.pdf

Yellow Nutsedge Control

Revised by Brooke M. Garcia, original post by Dr. Jared Hoyle

We have been receiving some precipitation recently across the state of Kansas. Even if you have received little rain in your area, you may be seeing yellow nutsedge popping up everywhere. Yellow nutsedge does favor moist soils but it can also grow in well-drained sites.

 

One of the easiest ways to identify yellow nutsedge is by a couple special features;

  • erect
  • persistant
  • yellow inflorescence
  • gradually tapering leaves to a sharp point
  • tubers not in chains
  • triangular stem

To control yellow nutsedge, if you can get applications out before tuber production then you will see increased control. But beware, yellow nutsedge will continue to grow as long as the environment is favorable for growth, so more than one application may be necessary.If using a herbicide application timing is critical. During mid-summer, yellow nutsedge starts making tubers and if you apply herbicides before tuber production you will get better control. If you wait until the yellow nutsedge is big and starting to make tubers then you will be playing catch-up all year. So sooner is better.  Don’t wait for it to get too big.

Here are some options for yellow nutsedge control for turfgrass professionals;

  • pyrimisulfan (new herbicide that provides yellow nutsedge control)
  • sulfentrazone
  • halosulfuron
  • iodosulfuron
  • mesotrione
  • bentazon
  • triflozysulfuron
  • flazasulfuron
  • sulfosulfuron

There are many different products out there that contain these active ingredients so just make sure you have an active ingredient that has yellow nutsedge control! Also make sure you check for turfgrass tolerances.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application.

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Be sure to follow our KSU Turf Facebook page: www.facebook.com/KSUTurf

Today is the start of…. National Pollinator Week!

By Brooke M. Garcia

Happy National Pollinator Week! National Pollinator Week occurs every year around mid-June. This year, June 22-28th, 2020 is dedicated to celebrating pollinators and promoting how we can protect them in the landscape and/or environment. What can you do this week to protect or promote a pollinator?

Here are some ideas to show your support:

  • Plant native plants in the landscape
  • Educate employees on pesticide safety
  • Display pollinator artwork and outreach materials in your office lobby
  • Highlight Pollinator Week in a newsletter, blog, or magazine
  • Host a nature walk or pollinator expert lecture

Use the hashtag #pollinatorweek to promote pollinator week, events and resources shared.

For more information about National Pollinator Week, you can visit the official website.

Visit our K-State Pesticide Safety and Integrated Pest Management Facebook page to stay tuned with educational topics related to pollinators, pesticide safety, and IPM.

Upcoming #KStateGardenHour Topics – REGISTER NOW!!!

By Brooke M. Garcia

The K-State Garden Hour is a successful online webinar series, hosted by K-State Research and Extension. Each week, the series is hosted on Wednesdays from 12:00 – 1:00 P.M. CST. This virtual series will provide information on a variety of horticultural topics, as well as highlight educational topics related to plant selection, entomology, plant pathology and integrated pest management.

Here are the upcoming topics for the month of July:

To learn more about any of the topics featured, visit the K-State Garden Hour webpage: K-State Garden Hour Webinar Series

Each webinar in the series has a separate registration page. You will need to click on each webinar that you would like to attend. Please preregister for each session online. 

You can also find, promote and share each webinar on Facebook, via the Facebook Events

If you have any questions, please email our team at ksuemg@k-state.edu.

Consider Postemergence Crabgrass Control When Plants are Young (Now)

By Dr. Jack Fry

Crabgrass is now becoming quite visible. If you didn’t apply a preemergence herbicide, or had some crabgrass emerge even where it was applied, now is the time to consider postemergence control. If a preemergence herbicide was applied, but you’re still seeing crabgrass, there may have been variability in uniformity of delivery over the area to which it was applied. If new sod was laid recently, it’s common for crabgrass to emerge through the seams. Control is easier when plants are young, for they are rapidly growing and have a thinner leaf cuticle. Make sure the crabgrass plant isn’t under stress before you apply the herbicide; rainfall or irrigation on the area within a few days prior to application can help ensure the herbicide is absorbed and translocated. Dr. Hoyle wrote a nice summary of best approaches to postemergence crabgrass control here:  https://blogs.k-state.edu/turf/postemergent-crabgrass-control

In addition, consider purchasing Turf Weed Control for Professionals, which was developed by cooperatively by numerous universities in the Midwest, including K-State. It can be purchased as a hard copy or a PDF download here:  https://mdc.itap.purdue.edu/item.asp?Item_Number=TURF-100

Young crabgrass emerging in a stand of zoysiagrass in Olathe this week.  Postemergence herbicides are most effective when crabgrass plants are young, and not under drought stress.

NEW ONLINE GARDEN SERIES: K-State Garden Hour

By Brooke M. Garcia

Join K-State Research and Extension for a new gardening series called “K-State Garden Hour.” This free weekly series will be every Wednesday from 12:00 p.m. – 1:00 p.m. via Zoom. This virtual series will provide information on a variety of horticultural topics, as well as highlight educational topics related to plant selection, entomology, plant pathology, and integrated pest management.

Whether you’re new to gardening or have some experience, you’re sure to learn something new. Discussions will be led by K-State Extension Professionals throughout the state of Kansas. This event is limited to 500 participants. Sessions will be recorded and posted here after each event: https://hnr.k-state.edu/extension/info-center/k-state-garden-hour-webinar-series/k_state_garden_hour.html

Here are the featured topics for the next few weeks:

Wednesday, May 20th: Native Plants in the Landscape – Pam Paulsen, Reno County Horticulture Extension Agent

  • Native plants can be a great addition to your landscape. They are well adapted to local growing conditions and serve as important food sources for beneficial insects, birds and other wildlife. Pam will cover a number of native plant species and how they can be used in your landscape.

Wednesday, May 27th: Taking Care of Tomatoes – Tom Buller, Douglas County Horticulture Extension Agent and Judy O’Mara, K-State Plant Disease Diagnostic Lab

  • Many maintenance techniques can improve your tomato plant health, while also increasing plant yield. Tom will cover tasks including training, irrigating, pruning and insect management and Judy will discuss tomato diseases that occur in Kansas and how to manage them.

Wednesday, June 3rd: Making and Supporting Pollinators In The Garden – Jason Graves, Central Kansas District Horticulture Extension Agent

  • Making and supporting pollinators should not be optional since they are essential to maintaining the vast number of ecosystem services we all rely on every single day. Jason will explore who our pollinators are, understanding pollinator needs and what we can do to make and support pollinators in our own yards.

Each webinar in the series has a separate registration page. You will need to click on each webinar that you would like to attend. Please pre-register for each session herehttps://hnr.k-state.edu/extension/info-center/k-state-garden-hour-webinar-series/k_state_garden_hour.html

You can also find, promote, and share each webinar on Facebook using our hashtag #KStateGardenHour and via our Facebook Events: https://www.facebook.com/pg/kstate.hnr/events/?ref=page_internal

Three Steps to Choosing Potting Media for Outdoor Use

By Dr. Cheryl Boyer

There are a lot of choices in the potting media aisle of your local garden center. If you don’t know what you’re looking for, it can be a confusing experience to read the label. Fortunately, there are three easy steps/considerations for screening the available choices down to one that works for your needs.

Step 1: What are you using it for?

It does make a difference whether you are planning to use media in a container or as a soil amendment in a raised vegetable bed or landscaping bed. Some materials are designed to hold water well while others are designed to drain well. What do you need for each of those situations?

  • Growing plants in containers: Generally, you want to use a peat-based soil-less substrate for this application. Do not use field soil. These products are engineered for success in season-long growth of annual plants in containers of reasonable size for consumer use (very large containers are a different discussion). Peat-based mixes almost always have a “starter charge” of fertilizer mixed in to get your plants growing, but you’ll need to supplement with fertilizer as the season progresses. Old potting media has likely lost its starter charge and may, in fact, become hydrophobic (repels water) over time. You’ll need to spend some time rewetting and mixing old potting media for a new season if you intend to re-use it.
  • Amending a landscape bed or raised bed: Products containing peat should not be the primary component but are acceptable in small quantities. Field soil mixed with compost and perhaps a coarse pine bark-size material is best in this situation. The objective is to enrich your existing soil with natural material that will break down over time and in the meantime provide nutrients and aeration for roots to grow well. Make sure to apply the material and mix/till it into a broad area and not just a single planting hole or your new plants may experience the “soup bowl effect” and succumb to rapid decline. Check with your local landscape contractor to get a large volume of soil delivered, perhaps even mixed with compost from a local municipal composting facility.

Step 2: Understanding Major, Minor, and Specialty Components

These materials are regionally sourced and often composted to reduce particle size. Some materials are manufactured for the purpose of being used in potting media and many more are by-products of other industries. They are all fine as components but look at the label to understand how much of each “ingredient” is mixed, by volume, into the product you’re purchasing. If that information isn’t on the bag, be wary of purchasing.

  • Major components: Bark (or “composted forest products”), peat (this might be defined by type of peat which often refers to the source material or the coarseness), soil (don’t pay for this unless it’s local/regional and advertised as a single-component soil amendment—not as a potting media), manure, sand. Other waste-product alternative materials such as coconut coir and wood fiber are also great to use, but they’re not seen as often in consumer-level products.
  • Minor components: Perlite (little white pellets–it’s for aeration, not fertilization), vermiculite (shiny heat-expanded rock pieces), rice hulls (also for aeration with an added bonus of weed control when applied to the tops of containers). These are the most common.
  • Specialty components: mycorrhizae (symbiotic fungal organism that, mixed in, can be very beneficial in a container system by expanding the root capacity to take up nutrients and water, it’s less effective in field soil where these organisms are already abundant), fungicide (some products are designed to address specific fungal growth issues).

A note about manure and compost: These are good organic materials; however, you must be careful that the source can guarantee the material that produced the manure (hay, pasture grass, etc.) was not treated with herbicide. Many herbicides used in pasture management have a very long half-life and can persist in your landscape beds, killing desired plants.

A note about organic products: While most media components are considered “natural” and are likely produced using organic practices, few will be labeled as organic simply due to the nature of the organic certification process. An organically labeled product is not inherently better than another, though if you’re looking for a bagged manure product, organic will ensure the absence of herbicide residue.

Step 3: Mixing and Managing

Knowing what you’re working with and what you’re trying to do with it will help you understand how to manage it in practical use. These materials may also listed on the ingredient list and it’s helpful to know what to expect.

  • Lime: One special challenge we have in Kansas is that we have a lot of limestone around, which raises the pH of our soil and our water. You may notice that many bagged products include lime or limestone as a fertilization amendment. This is because most soil-less media components are very low in pH, or acidic, and they’re trying to get the mix to be pH neutral (so that most nutrients are available for plant uptake). In Kansas, most of our soils are on the high pH, or alkaline, side. It is to our advantage to apply soil-less products that are low in pH because that will help to neutralize our native soil. We don’t need the added limestone, but it’s unlikely you’ll find a product that doesn’t have it mixed in. For sure, don’t add more!
  • Fertilizer: As mentioned earlier, most bagged products have a “starter charge” of fertilizer. You won’t need to add anything immediately, but within a few weeks you’ll need to apply a water-based fertilizer (immediately available to plants) and/or a long-term slow-release fertilizer product. These usually come rated for months of use. A short-term product (3-4 months) may sound like it will last all summer, but if it gets really hot outside the pellets may release early (if temperature is the mode of operation). Combining a shorter-term product with a longer term one (8-9 months) may cover your needs for a longer time.
  • Wetting agent: Some products, like peat, are harvested and packaged in a very dry state and may need help retaining water when ready for use. This will likely be pre-mixed, though if you can tell it’s very dry you may want to spread it in a wheelbarrow and mix in some water (and maybe your own re-wetting agent) until it’s consistent.
  • Watering: Containers will need to be monitored for water more frequently than landscape beds, but they all need to be checked. This will vary in every situation, so you’ll need to keep an eye on it until you understand how all of the components are functioning together.

Potting media products are remarkably similar once you get past the packaging. Read the ingredient label (just like in the grocery store), find what you need for your application, and then choose the product that best meets your needs and your budget. Choose on price only after you’ve leveled the playing field of similar products.

Got questions about an unusual component? Let me know—I love a good alternative material discussion. Here is my email: crboyer@ksu.edu